package com.tianqi.tools;

import java.text.DecimalFormat;
import java.text.FieldPosition;
import java.text.Format;
import java.text.NumberFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;

public class IdGenerateTool {

	/** The FieldPosition. */
    private static final FieldPosition HELPER_POSITION = new FieldPosition(0);

    /** This Format for format the data to special format. */
    private final static Format dateFormat = new SimpleDateFormat("yyMMddHHmmssS");

    /** This Format for format the number to special format. */
    private final static NumberFormat numberFormat = new DecimalFormat("00000");

    /** This int is the sequence number ,the default value is 0. */
    private static int seq = 1;

    private static final int MAX = 99999;

    /**
     * 时间格式生成主键
     */
    public static synchronized String generateId() {

        Calendar rightNow = Calendar.getInstance();

        StringBuffer sb = new StringBuffer();

        dateFormat.format(rightNow.getTime(), sb, HELPER_POSITION);

        numberFormat.format(seq, sb, HELPER_POSITION);

        if (seq == MAX) {
            seq = 1;
        } else {
            seq++;
        }

        return sb.toString();
    }
	
}
